The Syrian aircraft was intercepted Tuesday by an Israeli surface-to-air Patriot missile after it infiltrated an Israeli-occupied area, Israel's military said.

"A warplane that penetrated Israeli territory was successfully shot down a short while ago by the air defense systems along the Syrian border," the army said in a statement.

Israeli military spokesman Aryeh Shalicar told German press agency DPA it was the first such incident to take place since the 1970s.

According to Israel army radio, as quoted by press agency AFP, the MiG-21 fighter jet was struck as it approached the Israeli sector of the Golan, and its wreckage landed on the Syrian side of the plateau. It added that the circumstances surrounding the incident were being investigated.

Israeli Defense Minister Moshe Yaalon said Israel would not allow elements, whether "a terror group or a state, to threaten our security and breach our sovereignty."

Accusations of supporting IS

Syrian state TV, meanwhile, quoted a military source who confirmed the downing of the jet and described it as an act of aggression within "the framework of (Israel's) support for the terrorist (Islamic State) and the Nusra Front" and coinciding with US-led air strikes against "Islamic State" (IS) in Syria. The US and partner nations across the region, announced that they had commenced airstrikes against IS in Syria on Tuesday. Israel did not participate.

Since Syria's civil war broke out in 2011, much of the Golan Heights to Israel's northeast has been taken over by rebels seeking to overthrow President Bashar al Assad. In recent weeks the plateau has been the site of intense fighting between the al Qaeda-linked Nusra Front and Assad's forces, and the regime has conducted frequent airstrikes - some of them close to Israeli positions - in an attempt to recover lost ground.

Disputed territory

It's not unusual for stray rocket fire to land on Israel's side, but there have also been instances of targeted attacks, for example, in which an Israeli teenager was killed in June.

Israel took control of around 1,200 square kilometers (460 square miles) of the Golan during the Six-Day War of 1967. In 1981, it annexed the area in a move that was opposed by the international community, while some 510 square kilometers, or about a third of the region, remains under Syrian control.

nm/es (Reuters, dpa, AFP)